Gas burner



Nov. 18, 1941. E. J. HAEDIKE GAS BURNER Filed Deb. 7, 1938 2 Shets-Sh eet 1 N Im/enzor Edward Jhaedjlm a the foregoing character embodying a Patented Nov. 13,1941 7 eAs'nUnNEa Edward 1., Haedike, Chicago, 111., assignor to I National Machine Works, Chicago, 111., a "corporation of Illinois Application December 7, 1938, Serial No. 244,371 17 Claims. "(01. 158-109)- The present invention relates to improvements in forced draft gas burners adapted for industrial and domestic use.

One of the objects of the present inventionis to providea novel, fuel gas burner which has a substantially cylindrical discharge end adapted to be inserted into a combustion chamber and which is interchangeable with various standard" types of oil burners, particularly in conversion installations. l

. Another object of the invention is to provide a new and improved fuel gas burner having an annular name in close contact with a concentric stream of secondary air under low pressure.

A further object is to provide a novel fuel gas burner of the foregoing character which is sim-- ple, compact and inexpensive in construction and which is quiet, eilicient and economical in operaburner.

Other objects and advantages will become ap parent as the description proceeds.

In the accompanying drawings, Figure 1 is a fragmentary-longitudinal. vertical sectional .view: of a gas burner embodyln's ethe features of the invention.

' Fig. 2 is a fragmentary plan view.

- Fig. 3 is a fragmentary vertical sectional view taken partially along the line 8-8 of- Fig. 4 isad'ight end elevational view.

The casing 2 may be of any suitable form, and as-he'rein shown is cylindrical in shape, with one end telescopically receiving the outer end of the burner tube I, and the other end formed with an access opening 4 closed by a removable cover plate 5. Twoparallel vertical rods 8 extendadjustably through two apertured lugs 1 on opposite sides of the casing 2, and are adapted to be secured therein by means of set screws 8. The rods 8 constitute supporting legs adapted to rest on a' suitable foundation, such as a floor (not shown).

Air for combustion is supplied at a low pressure to the chamber 3 froma blower 8, In the present instance; the blower 9 has. a peripheral housing III which is rigidly mounted directly on the casing 2, and preferably is integral therewith.

' other side of the blower housing I. Mountedon .between and interconnected with the disks.

Referring more particularly tothe drawings,

I the burner constituting the exemplary embodiment of the invention comprises a burner housing which isv preferably in the form of an elongated metal tube One end of the burner tube I is supported by and opens to a casing 2 which defines a wind box or low pressure air chamber 3 adapted to supply all of the air, both primary and secondary, for complete combustion. It will be understood that the other end of the burner tube l is adapted to be mounted within a well or opening (not shown) in one wall of a furnace combustion chamber (not shown) The blower housing It has an axial atmospheric air inlet II in one side, and a tangential air outlet |2- opening through the top wall of the casing 2 to the chamber 8. A plate is integral with a horizontal bracket i8 is bolted to and closes the the bracket I3 is an electric drive motor ll havinga shaft l5. p

The motor shaft l5 projects centrally through an opening l8 in the plate It into the blower housing II, and supports a rotor [1 having a closed inner end disk l8, an annular outer end disk It in alignment with the air inlet 1 I, anda plurality of peripherally spaced radial vanes 20 A suitable damper 2| is adjustably mounted in operative associationwith the air inlet ll to con: trol the amount of air supplied to the chamber 8 and hence the air pressure therein.

Mounted within and extending along the bottom of the bumer tube l is a mixing tube. 22

having an inlet cone 28 and an expanding-outlet cone 24; The inlet cone 28 is closed by an end wall 25 and is provided in the top adjacent the wall with an air inlet opening 28 in communication with the air chamber 3. A shutter plate 21 is pivotally bolted to the mixing tube 22 forangular adjustment into different degrees of registration with the inlet opening 28 to control the supply of primary air. Removably threaded through the end wall 25 to extend axially into the inlet cone 23 is a gas or fuelnozzl'e 28. An orifice body 28 having an axial discharge orifice 30 of selected size is removably seemed, in. the dischargeend of the nozzle 28. Different sized orifices may be employed for different types ,of fuel gas, and to vary the rate of input and capacity of the burner. Secured to the inlet end of the nozzle 20 is a 'r pipe. fitting 3| closed at the J chamber.

outer end by a removable screw plug 32 and conncted at the side to a gas supply pipe 33. The pipe 33 extends through an opening 33* in'one side of the casing2 for connection to a suitable source (not shown) of fuel gas under pressure,

and is secured in position by a set screw 33 to support the outer end of the mixer assembly. It willbe noted that removal of-the cover plate 5 affords access to the shutter 21 and the plug 32, and that removal of the latter affords access to the orifice body 29, so that the ratio of fuel to air and the ratio'of primary air to secondary air may be quickly and conveniently adjusted.

The discharge end of the mixing tube 22 is rigid, and preferably formed integral, with a burner head 34 which is arcuate in shape and formed with. an arcuate fuel-air mixture discharge port 35 opening from the expanding'cone 24. The terminal portion of the head 34 is closely encircled by the burner tube whichserves to support the discharge end of the mixer assembly.

In the present instance, the periphery of-the tral recess 39 openat the top. A flanged pilotv tip plate 40 in the form of an' outwardly opening cup is rigidly secured in position, as by welding,"

between the spaced side margins 38 of the burner head 34, and projects downwardly into the recess 39. The upper flange portion of the plate 48 extends concentrically within the burner tube I so as to complete the full circular form of the burner head assembly. The lower flange portion of the plate 40 extends in concentrically spaced relation to the inner surface of the burner head .34 to define an intermediate arcuate or partially annular secondary air discharge port 4| in munication with the pressure chamber 3.

In operation, fuel gas under pressure discharges through the orifice 30 at a high velocity, and induces the flow of'a proportionate amount of primary air under a low pressure from the chamber 3 through the opening 26 into thetube 22.' The pressure of the air is controllable by means of the damper 2|. The fuel and primary air are thoroughly mixed in the tube 22, and the resultant mixture issues under pressure from the arcuate fuel port 35 for combustion in the furnace Secondary air under pressure issues from the arcuate port 4| in a stream defining a closely spaced hollow internal air core. As a result, the fuel and air are intimately mixed to insure efficient and complete combustion; The mixture burns quietly and with a soft long annular flame. 4

A pilot burner is provided to ignite the fuel mixture. In the present. instance, the I pilot burner comprises a block 42 of refractory material mounted within the flanged trip plate 46 comaxially. through the disk 41, and the other ports I are annularly spaced, with the lowermost ports inclined to discharge downwardly. The inclined ports serve to keep the flame from blowing off the pilot tip, i. e., retards the pilot flame.

To support the burner tube 44 in position and for connection to a suitable source of fuel, a pilot mounting plate 50 is supported within an opening 5| in the top of the main burner tube by an adapter bracket or plate 52. This bracket has a base flange 53 arcuate in shape to conform to the curvature of the tube I, and circumscribing the opening 5|. One end portion of the bracket ,52 is formed with an inclined hood or top wall 54 which is integral with and rises from the flange 53- and which serves to close the end of the opening 5| adjacent the burner tube 44; The remaining portion of the bracket 52 is formed with an upstanding marginal wall 55 about the opening 5| and integral with and circumscribed by a horizontal top flange 56. The

mounting plate 50 is provided with an external marginal flange 51 resting on and secured to the flange 56, and the central portion thereof projects downwardly through the opening 5| and defines an upwardly opening well or recess 58. One end of the mounting plate 50 is formed with a wall 59 normal to and abutting the free edge of the hood 54, A fitting 60 integral with the base wall of the recess 58 is formed with a discharge bore 6| opening through the wall 59 and adapted to be connected through one of two tapped lateral openings 62 to a tube 63' leading to a source of fuel gas (not shown). A lighter is mounted in the other opening 62.

The passage 6l inthe plate 50 is connected to the burner passage 46 through a proportional fuel and air mixer. This mixer preferably comprises a Venturi tube '64 threaded at the discharge end into the burner tube 44 and having a plurality of peripherally spaced apertures 65' opening from the chamber 3 to the inlet end.

and formed with'a central burner tunnel or well' A tubular nozzle 66 with a discharge orifice 61 is threaded at one end into the inlet end of the mixing tube 64 and at the other endinto the passage 6|.

In operation, fuel gas under pressure issues from the orifice 61 at a high velocity, and induces the flow of, a proportionate amount of air under a low pressure from the chamber 3 through the apertures 65 into the tube 64. The fuel and air are thoroughly mixed in the tube 64, and the resultant mixture passes through the burner ports 43 for combustion to providega pilot flame. The refractory. block 42 protects'the pilot burner 44 from becoming overheated by reflected or radiant heat from thecombustion chamber, and also serves to promote combustion.

Automatic means may be employed for controlling the supply of fuel gas to the main burner. This control means includes a fuel bleed line or conduit 66 which is opened and closed respectively to institute and cut off the main supply of fuel, ,The conduit 68 is connected to a passage 69 in the wall of the pilot burner tube 44 discharging to the burner well 43 so that the bleedlnggas will pass into the combustion chamber and enlarge the pilot flame. Other primary details of the control means form no part of the present invention, and hence are not disclosed.

A safety valve 10 is provided to automatically close the conduit 68 and thereby effect a cut-off of the main fuel supply in'the event thatthe pilot flame isextinguished. The valve 10 is interposed in the conduit 68, and is mounted in the recess of the plate ill, the portion of the conduit from the valve .to the passage 69 extending through an opening 1| in the wall 59. The valve 10 may be of any suitable standard type adapted to close automatically in response to the temperature drop resulting when the flame is extinguished, and hence is not disclosed-in detail.

' erallyiembraced and supported by said tubular It is sufllcient to state that the valve is controlled by a suitable thermocouple I2 to which ity is connected by a. control lead 13 extending through an opening ll in the wall 59. The hot junction of the thermocouple 12 projects through a lug 15 on the burner tube ll into the burner well 43 and is inclined downwardly intothe path of the pilot flame. I

The novel fuel gas burner herein disclosed has a long soft annular flame in direct contact 'internally with a conforming stream of secondary. air. As aresult, combustion isquiet, complete and efficient, only a small amount of excess air being present.

It will be evident that the burner is readily and conveniently adjustable for operation under widely different conditions, Thus, the burner may be adjusted to vary the capacity, to' vary the ratio of fuel and air in the primary mixture and the ratio of primary and secondary air, and'to adapt the burner for different types of fuel gas such, for example, as manufactured gas, natural gas or a mixture of the two. Most of the burner structure is locatedextemally of the furnace,

and consequentlythe foregoing adjustments can be made without disturbing the installation.

The fuel burner is simple, compact and inexpensive in construction and it is especially adapted for use as a conversion burner in domestic installations. The burner head is round and interchangeable with various types of fuel oil burners.

I A novel and advantageous pilot burner is also provided. The pilot burner receives a controlled proportionate mixture of fuel and air and discharges into the annulus of the main burner flame. The tip of the pilot burner is protected from becoming .overheated by refractory material which also serves to promote combustion. The pilot burner is also removable for inspection without disturbing the installation of the main burner. All of the air for combustion, not only for the main burner but also for the pilot bumer, is received from a common low pressure source.

I claim as'my invention:

1. In a fuel gas burner, in combination, a cy-' lindrical burner head having arcuate port means formed and'arranged to discharge a coaxial arcuate stream of a fuel-air mixture-under pressure, and having concentric arcuate port means formed and arranged to discharge a coaxial arcuate stream of secondary air inside of and closely contiguous to said first mentionedstream, and a pilot burner arranged to discharge a pilot stream of fuel centrally of said last mentioned port means into the hollow core zone of said two first mentioned streams.

2. In a gas fuelburner. in combinatlon, a cask ingconstituting anair chamber and having atubular discharge end, means for supplying air under pressure mixerin said'casing and havinga primary air inlet opening from said casing and a fuel supply orifice nozzle and having an expanding discharge cone, means for supplying gaseous fuel to said nozzle, and a circular burner-head integral with the end of said discharge cone and periphto said casing, a fuel and airdischarge end, said head being shaped to define concentric arcuate discharge ports in communication respectively with said chamber and said discharge cone. p v r 3. In a. gas fuel burne r,-in: combination,a casing constituting an air chamber and having atubular discharge end, means for supplying air under pressure to said casing, a fuel-air mixing. tube in said casing and having a primary air inlet opening from said casing ,and a fuel supplyorifice nozzle, means for directing gaseous fuel under pressure to saidnozzle, and a burner head connected with said mixing tube, said head defining concentric discharge-ports in a plane transverse to the axis of said mixing tube and in communication respectively with said chamber and said mixing tube and extending arcuately through the major portion but less than the entire portion of the circumference of said discharge end, said port which communicates with said mixing tube having the center of its arcuate configuration disin said notch and completlnglthe circular form of-said head, said plate projecting into the center space of said head and coacting with saidphead todefine an arcuate air discharge port concentrio with said first mentioned port, means for supplying air to said last mentioned port, and a pilot burner mounted to discharge throughsald plate. 1 v

' 5. In a fuel gas burner, in combination, an arcuate burner head member defining an arcuate fuei-air mixture discharge port, means for supplying a fuel-air mixture to said port, a pilot plate rigidly secured to said member between 'the ends of said port and coacting with said head to define an arcuate air discharge port concentric with said first mentioned port, means for supplying air to said last mentioned port, and a pilot burner mounted to discharge. through said plate.

6. In a fuel gas burner, in combination, a burner head defining an arcuate fuel-air mixture discharge port, means for supplying a fuel-air mixture to said vport, a cup-shaped pilot plate within said head and coacting therewith to de fine an arcuate air discharge port concentric with said first mentioned port, means for supplying air to said last mentioned port, a re'fractory block mounted in said plate and formed with a. tunnel, a pilot gas burner having a plurality of fuel discharge ports mounted to discharge into said tunnel, certain of said last mentioned ports being inclined to direct the issuing fuel toward the side wall of said tunnel, and means for supplying a fuel-air mixture to said pilot burner.

7. In a fuel gas burner, incombinatioma bumer tube having a circular discharge end, a closed casing connected to the other end of said tube andcoactlng therewith to define a low pressureair'chamber, a blower rigid with said casing and discharging thereto, said blower having an adjustable air ln1et, a fuel and air mixing tube extending through said. burner tube and into 'said casing, an orifice fuel nozzle mounted in the inlet end of said mixing tube and having a fuel supply line extending from said casing, the inlet end of said mixing tube having an air inlet opening from said chamber and controlled by an adjustable damper to vary the ratio of primary air to secondary air, an arcuate burner head'on the discharge end of said mixing tube closely encircled by the discharge end of said burner tube and defining an arcuate fuel-air mixture port communicating with said mixing tube, a pilot tip plate rigidly mounted in the burner head and coacting with the inner arcuate surface thereof to define an arcuate secondary air port in communication 'with said chamber and concentric with said mixture port, and a pilot burner mounted on said burner tube and discharging through said tip plate substantially centrally of said ports.

8. In a fuel gas burner, in combination, a burner tube having a circular discharge end, a

' closed casing connected to the other end of said tube and coacting therewith to define a low pressure air chamber, a blower rigid with said casing and discharging thereto, said blower having an adjustable air control damper, a fuel and air mixing tube extending through said burner tube and into said casing, an orifice fuel nozzle mounted in the inlet end of said tube and having a fuel supplyline extending from said caschamber and concentric with said mixture port.

9. In a fuel gas burner, a casing defining a low pressure air chamber, means for supplying air under pressure to said chamber, a burner head having fuel-air mixture discharg port means and'having air discharge port means opening plying a fuel-air mixture to saidpilot burner.

12. In a fuel gas burner, in combination, a burner head having a fuel-air mixture discharge port and a contiguous secondary air port, means for supplying a fuel-air mixture to said discharge port, means for supplying air to said air port, a refractory block mounted in said head contiguous to said ports and formed with a tunnel displaced laterally from saidports and out of the direct path of fuel and air issuing therefrom, a pilot gas burner having a plurality of fuel discharge ports mounted to discharge into said tunnel, certain of said last mentioned ports being inclined to direct the issuing fuel toward the side .wall of said tunnel, and means for supplying fuel to said pilot burner.

13. In a gas fuel burner, in combination, an

elongated casing constituting an air pressure chamber and having a discharge end, means for supplying air under superatmospheric pressure tosaid casing, a burner head in the discharge and of said casing and having fuel discharge passages and secondary air discharge passage means in contiguous relationship, said passagemeans being open tosaid casing to receive air therefrom, aplurality of independent fuel and air proportioning mixers mounted within said casing to discharge fuel mixtures to different ones of said fuel passages, each fuel mixer including a mixing tube having a primary air inlet opening directly from the interior of said casing to receive air by induction therefrom and including a fuel jet orifice to discharge fuel under pressure into said tube, and means for adjustably proportioning the ratio of primary to secondary air for the fuel discharged from at least one of said mixers independently of the other mixer or mixers.

14.j In a gas burner,v in combination, a casing constituting an air chamber and having a tubular discharge end, means for supplying air under pressure to said casing, a fuel and air mixer in from said chamber, a fuel and air mixer having an adjustable air inlet opening from said chamber'andfuel inlet means and discharging to said first mentioned port means, a pilot burner, and a fuel-air mixer connected to said pilot burner and having an air inlet opening from said chamber and fuelinlet means.

10. In a fuel gas burner, in combination, an

elongated burner housing having an o'pening'in one side wall and defining an air pressure chamber, an adapter plate secured to said w 9. 1 about said opening, a mounting plate inset .irr-said adapter plate, a main burner unit mounted in one end of said housing and receiving air from said chamber, and a pilot burner supported'from said mounting plate within said housing and discharging from said housing "adjacent said J main-burner unit..

11. In a fuel gas bumer, in combination, a

burner head defining an arcuate fuel-air mix-.

said casing, said mixer-including an elongated mixing tube with an inlet cone opening to the interior of said casing and an expanding discharge cone and extending longitudinally of said casing, and including a fuel supply orifice nozzle discharging axially into said inlet cone, means for supplying gaseous fuel under pressure to said nozzle, the discharge end of said expanding cone merging smoothly from a conical form. into aw arcuate form of substantially greater diameter to constitute a burner head with an arcuate discharge port extending through the major portion of the circumference of said casing and with the axis of said head paralleling that of said ex- 15. In a gas fuel burner, in combination, a

casing constituting an air chamber and having a tubular discharge end. means for supplyingair under pressure to said casing. a fuel and air mixing tube mounted in and extending longitudinally and eccentrically of said casing,'said mixin g tube having an air inlet open to said casing and having, a discharge end with an arcuate outlet port and closely circumscribed by said tubular discharge end bf said casing, means for supplying fuel under pressure into the inlet of said tube whereby to induce the fiow of primary air from said easing into said inlet and to produce a fuel mixture to issue from said port, and

means in said tubular discharge end of said casing for causing discharge of secondary air from said casing contiguous to said port.

16. In a fuel gas burner, in combination, an elongated burner housing having an opening in one side wall and defining an air pressure chamber, a mounting plate supported in and closing said opening and projecting into said housing, a

main burner unit mounted in one end of said ing a fuel supply orifice nozzle discharging axially into said inlet cone, means for supplying gaseous fuel under pressure to said nozzle, the

' outer end of said discharge cone flaring smoothly housing and receiving air from said chamber, v

and a pilot burner supported from said mounting plate within said housing and discharging from said housing adjacent said main burner unit.

1'7. In a gas fuel burner, in combination, a casing constituting anyair chamber and having a tubular discharge projection thereon with an open end, means for supplying air under pressureto said casing, a fuel and air mixer in said casing, said mixer including an elongated mixing tube with an inlet cone opening to the interior of said'casing and an expanding discharge cone,

said discharge cone being arranged to-project longitudinally through said casing extension-but eccentrically located with respect to the longitudinal axis of the latter, said mixer also includoutward into an enlarged integral head portion having an arcuate exterior contour conforming to the curvature of the encircling end portion of said casing and snugly flttedtherein, said'head portion of the discharge cone having a deep indentation' in one side thereof and in which the indented wall is dished down to coact with the opposite wall of the head to define an arcuate end portion at the outer end of said head for the emission of fuel and primary air, and means substantially filling the space left in the end of said casing extension by said indentation but spaced sufilciently from said head portion to define with it an arcuate secondary air emission portrunning along the inner perimeter of the first mentioned port and communicating with the interior I the casing of said casing for directing 'air from for secondary combustion.

- unwairn J; HAEDIKE. 

